When in a discussion marked by terseness Sankara in an aside dilates on a topic, that is I think an indication that an unfamiliar line of argument is being broached. Santayana makes a similar point about what he calls animal faith namely that pre-theoretic, arational, immediacy of our confrontation with the world. He used it in Scepticism and Animal Faith to impugn the mentalistic folly of Cartesian foundationalism. Sankara drops in the claim that even animal consciousness involves superimposition/adhyasa. There is no subject/object consciousness without it. Not that animals can parse in this manner and that is just the point. Here we have something more basic than analysis.
Moreover there is no difference (of the learned) from the animals (in regard to empirical behaviour). Just as animals and others turn away from sound etc. when these appear to be unfavourable after their ears come in contact with them, and they move towards these when they are favourable; and they move towards these when they are favourable; and just as by noticing a man approaching them with a raised stick, they begin to run away thinking, “This one wants to hurt me”, and they approach another carrying green grass in his hands, similarly even the wise are repelled by the presence of strong, uproarious people with evil looks and upraised swords, and are attracted by men of opposite nature. Therefore the behaviour of men with regard to the means and objects of knowledge is similar to that of animals. And it is a familiar fact that the animals use their means of perception etc. without discrimination (between the body and the Self). From this fact of similarity, the conclusion can be drawn that so far as empirical behaviour is concerned, the use of the means of perception by the wise is similar to that of lower animals, (it being a result of superimposition).(from the preamble to Brahma Sutra Bhasya by Sankara.)